Fig. 2. Principal components ordination of bulk soil treatments through time. Percentage of variance explained is indicated on each axis. Symbols indicate sampling date. The four plots show: (a) control, (b) leachate, (c) leached straw, and (d) unleached straw treatments. Ellipses enclose samples from early (dashed line) and late (solid line) samplings, with indicator PLFAs for each group listed. No significant temporal trends were observed in the control but significant temporal trends were observed for all amended treatments based on multi-response permutation procedure (MRPP) analysis (p < 0.001).